Problem	Presentation	Laboratory/radiographic findings	Treatment
Impingement	Positive impingement signs, painful motion, night pain	Radiographs may be normal or may show outlet obstruction (spurs, type 2 or type 3 acromion), aided with lidocaine injection	NSAIDs, rehabilitation, subacromial steroid injection, subacromial decompression
Rotator cuff tear	Weakness, atrophy; end result of chronic impingement, frequently precipitated by injury	Radiographs may show decreased subacromial space, osteophytes; MRI shows tears	Rehabilitation, especially in older patients; surgery in younger patients
Biceps tendon rupture	Bulge in the distal humerus (“Popeye” muscle), usually precipitated by injury; weakness in the supinators (20% loss), weakness in the elbow flexors (8% loss)	Radiographs normal or same as in impingement	NSAIDs, rehabilitation, repair in younger patients for both strength and cosmesis (competitive body builders)
Acute calcific tendinitis	Severe acute shoulder pain, very painful, restricted motion, tenderness on greater tuberosity	Radiographs show calcific deposits	NSAIDs and analgesics, rehabilitation and analgesics, steroid injection (usually), arthroscopic decompression (sometimes)
Adhesive capsulitis (frozen shoulder)	Loss of active and passive range of motion, pain at extremes of patient's motion; usually secondary to pain from a previous shoulder problem	Same as in impingement, tears	NSAIDs, rehabilitation modalities; if no improvement after 18 months, manipulation under anesthesia; most patients respond to a dedicated rehabilitation program
AC arthritis	Pain, swelling at AC joint, usually associated with impingement	AC joint narrowing, hypertrophy, spurs	Ice, NSAIDs, steroid injections in AC joint (difficult injection); resect distal clavicle if conservative treatment does not work
Glenohumeral arthritis	Chronic pain, loss of motion, crepitus, disuse atrophy	Joint space narrowing, changes in humeral head	NSAIDs, physical therapy, total shoulder arthroplasty in advanced cases
Septic arthritis	Acute painful limited motion, fever, chills	Elevated white blood cell count, erythrocyte sedimentation rate, synovial fluid white blood cell count >100,000 per mm3 (10.0 × 109 per L), positive culture and Gram stain; early radiographs normal, later radiographs show erosive changes	Intravenous antibiotics, surgical irrigation
Rheumatoid arthritis	Usually multiple, small-joint, symmetric	Radiograph shows joint space narrowing, osteoporosis; rheumatoid factor, erythrocyte sedimentation rate	NSAIDs, DMARDs, steroid injection
Gout	Podagra, monoarthritis	Serum uric acid, crystals in joint fluid	Colchicine, NSAIDs, allopurinol (Purinol, Zyloprim), probenecid (Benemid, Benuryl)
Lyme disease	Tick bite, erythema migrans	Lyme titer, characteristic rash	Antibiotics
Lupus erythematosus	Multiple joints affected	Antinuclear antibody, erythrocyte sedimentation rate	NSAIDs, antimetabolites
Spondylo-arthropathy	Sacroiliac joint	HLA B27	NSAIDs
Avascular necrosis	Predisposing factors such as steroid use, trauma, alcoholism; frequently idiopathic; painful motion	Early radiographs normal; later radiographs show humeral head flattening; proceeds to degenerative arthritis	NSAIDs, physical therapy, hemi- or total shoulder arthroplasty
Cervical radiculopathy	Radiating pain below shoulder or to upper back, decreased and painful range of motion in neck, positive Spurling's test,* neurologic changes in arms, normal shoulder examination	Radiographs show degenerative changes in cervical spine; MRI may show compressive radiculopathy	NSAIDs, physical therapy, traction, surgical Decompression
Tumor	Mass, history of smoking	Chest radiograph may show Pancoast's tumor	Surgery, chemotherapy
Thoracic outlet	Decreased pulses with provocative maneuvers	May require angiography	Surgery